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path: root/drivers/gpu/drm/i915/i915_query.c
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2018-05-29drm/i915/query: nospec expects no more than an unsigned longChris Wilson1-1/+4
nospec quite reasonably asserts that it will never be used with an index larger than unsigned long (that being the largest possibly index into an C array). However, our ubi uses the convention of u64 for any large integer, running afoul of the assertion on 32b. Reduce our index to an unsigned long, checking for type overflow first. drivers/gpu/drm/i915/i915_query.c: In function 'i915_query_ioctl': include/linux/compiler.h:339:38: error: call to '__compiletime_assert_119' declared with attribute error: BUILD_BUG_ON failed: sizeof(_s) > sizeof(long) Reported-by: kbuild-all@01.org Fixes: 84b510e22da7 ("drm/i915/query: Protect tainted function pointer lookup") Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> Cc: Lionel Landwerlin <lionel.g.landwerlin@intel.com> Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com> Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com> Reviewed-by: Lionel Landwerlin <lionel.g.landwerlin@intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20180522121018.15199-1-chris@chris-wilson.co.uk (cherry picked from commit a33b1dc8a732144e11cb4bf067d24ba51e6b8ab0) Signed-off-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
2018-05-28drm/i915/query: Protect tainted function pointer lookupChris Wilson1-3/+7
Smatch identifies i915_query_ioctl() as being a potential victim of Spectre due to its use of a tainted user index into a function pointer array. Use array_index_nospec() to defang the user index before using it to lookup the function pointer. Fixes: a446ae2c6e65 ("drm/i915: add query uAPI") Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> Cc: Lionel Landwerlin <lionel.g.landwerlin@intel.com> Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com> Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com> Reviewed-by: Lionel Landwerlin <lionel.g.landwerlin@intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20180521210530.26008-1-chris@chris-wilson.co.uk (cherry picked from commit 84b510e22da7926522a257cfe295d3695346a0bd) Signed-off-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
2018-03-08drm/i915: expose rcs topology through query uAPILionel Landwerlin1-0/+75
With the introduction of asymmetric slices in CNL, we cannot rely on the previous SUBSLICE_MASK getparam to tell userspace what subslices are available. Here we introduce a more detailed way of querying the Gen's GPU topology that doesn't aggregate numbers. This is essential for monitoring parts of the GPU with the OA unit, because counters need to be normalized to the number of EUs/subslices/slices. The current aggregated numbers like EU_TOTAL do not gives us sufficient information. The Mesa series making use of this API is : https://patchwork.freedesktop.org/series/38795/ As a bonus we can draw representations of the GPU : https://imgur.com/a/vuqpa v2: Rename uapi struct s/_mask/_info/ (Tvrtko) Report max_slice/subslice/eus_per_subslice rather than strides (Tvrtko) Add uapi macros to read data from *_info structs (Tvrtko) v3: Use !!(v & DRM_I915_BIT()) for uapi macros instead of custom shifts (Tvrtko) v4: factorize query item writting (Tvrtko) tweak uapi struct/define names (Tvrtko) v5: Replace ALIGN() macro (Chris) v6: Updated uapi comments (Tvrtko) Moved flags != 0 checks into vfuncs (Tvrtko) v7: Use access_ok() before copying anything, to avoid overflows (Chris) Switch BUG_ON() to GEM_WARN_ON() (Tvrtko) v8: Tweak uapi comments style to match the coding style (Lionel) v9: Fix error in comment about computation of enabled subslice (Tvrtko) v10: Fix/update comments in uAPI (Sagar) v11: Drop drm_i915_query_(slice|subslice|eu)_info in favor of a single drm_i915_query_topology_info (Joonas) v12: Add subslice_stride/eu_stride in drm_i915_query_topology_info (Joonas) v13: Fix comment in uAPI (Joonas) Signed-off-by: Lionel Landwerlin <lionel.g.landwerlin@intel.com> Acked-by: Chris Wilson <chris@chris-wilson.co.uk> Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20180306122857.27317-7-lionel.g.landwerlin@intel.com
2018-03-08drm/i915: add query uAPILionel Landwerlin1-0/+50
There are a number of information that are readable from hardware registers and that we would like to make accessible to userspace. One particular example is the topology of the execution units (how are execution units grouped in subslices and slices and also which ones have been fused off for die recovery). At the moment the GET_PARAM ioctl covers some basic needs, but generally is only able to return a single value for each defined parameter. This is a bit problematic with topology descriptions which are array/maps of available units. This change introduces a new ioctl that can deal with requests to fill structures of potentially variable lengths. The user is expected fill a query with length fields set at 0 on the first call, the kernel then sets the length fields to the their expected values. A second call to the kernel with length fields at their expected values will trigger a copy of the data to the pointed memory locations. The scope of this uAPI is only to provide information to userspace, not to allow configuration of the device. v2: Simplify dispatcher code iteration (Tvrtko) Tweak uapi drm_i915_query_item structure (Tvrtko) v3: Rename pad fields into flags (Chris) Return error on flags field != 0 (Chris) Only copy length back to userspace in drm_i915_query_item (Chris) v4: Use array of functions instead of switch (Chris) v5: More comments in uapi (Tvrtko) Return query item errors in length field (All) v6: Tweak uapi comments style to match the coding style (Lionel) v7: Add i915_query.h (Joonas) v8: (Lionel) Change the behavior of the item iterator to report invalid queries into the query item rather than stopping the iteration. This enables userspace applications to query newer items on older kernels and only have failure on the items that are not supported. v9: Edit copyright headers (Joonas) v10: Typos & comments in uapi (Joonas) Signed-off-by: Lionel Landwerlin <lionel.g.landwerlin@intel.com> Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com> Acked-by: Chris Wilson <chris@chris-wilson.co.uk> Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20180306122857.27317-6-lionel.g.landwerlin@intel.com